Chinese Potential Complements — 可能补语 (听得懂, 听不懂, 买得到)

A potential complement (可能补语 kě néng bǔ yǔ) answers the question "can the action be done, or not?" It is formed by placing 得 (positive) or 不 (negative) between a verb and its result or directional complement. 听懂 (understand by listening) becomes 听得懂 (can understand) and 听不懂 (cannot understand).

This is one of the most useful patterns in spoken Chinese because it expresses ability and possibility in a single compact structure. Instead of adding a separate modal verb, the 得/不 is tucked right into the middle of the verb phrase.

Positive form: verb + 得 + complement. 听得懂 (can understand), 看得见 (can see), 买得到 (can buy), 做得完 (can finish doing). The 得 means the action is possible or achievable.

Negative form: verb + 不 + complement. 听不懂 (cannot understand), 看不见 (cannot see), 买不到 (cannot buy), 做不完 (cannot finish). The 不 means the action is not possible or cannot be accomplished.

The complement after 得/不 is usually a result (懂, 完, 到, 好, 住) or a direction (来, 去, 起来, 出来). This is why potential complements are taught together with result complements.

Learn the highest-frequency pairs first: 听得懂/听不懂 (can/cannot understand), 看得见/看不见 (can/cannot see), 找得到/找不到 (can/cannot find), 买得到/买不到 (can/cannot buy), 做得到/做不到 (can/cannot do), 做得完/做不完 (can/cannot finish), 记得住/记不住 (can/cannot remember), 学得会/学不会 (can/cannot learn), 来得及/来不及 (can make it / cannot make it), 受得了/受不了 (can/cannot stand it), 用得了/用不了 (can/cannot use), 吃得下/吃不下 (can/cannot eat more).

Notice that some pairs are so frequent they have become fixed expressions: 来得及/来不及 (have enough time / be too late) and 受得了/受不了 (can tolerate / cannot tolerate) are used constantly in daily speech.

A result complement states that an action finished with a certain result: 我听懂了 (I understood — the result happened). A potential complement states whether the result is possible: 我听得懂 (I can understand — the ability exists).

The contrast is clearest in the negative. 没听懂 means "did not understand (this time)", while 听不懂 means "cannot understand (in general)". 没听懂 reports a specific failure; 听不懂 reports a general inability.

A useful test: potential complements use 不 (not 没) in the negative and never take 了. Result complements use 没 for the negative and can take 了.

Negation always uses 不 placed in the middle: 听不懂, 看不见, 买不到, 记不住. Do not use 没 for potential complements — 没听懂 means "did not understand" (result), while 听不懂 means "cannot understand" (potential).

To ask a yes/no question, use the A-not-A pattern by repeating both halves: 听得懂听不懂? (can you understand or not?). A softer question adds 吗: 你听得懂吗? (can you understand?). Both are natural in speech.

Both 能/可以 and potential complements express ability, but they differ in nuance and style. 能听懂 and 听得懂 both mean "can understand", yet 听得懂 is more colloquial and specific to the verb phrase, while 能听懂 sounds more formal or emphasizes permission and circumstance.

In practice, spoken Mandarin favors the potential complement for everyday ability: 我看不见 (I cannot see) is more natural than 我不能看见. Use 能/可以 when you want to stress general ability, permission, or a deliberate choice rather than the outcome of a single action.

The negative 不能 + verb usually means "must not / not allowed to" or "cannot (by rule)", which is different from 听不懂 / 看不见 (the result simply cannot be achieved).

Do not use 没 in a potential complement: 没听懂 (did not understand) is a result complement, not 听不懂 (cannot understand). Keep 不 in the middle for potential meaning.

Do not combine potential complements with 把-sentences. Because 把 preposes the object, the 得/不 structure cannot wrap around it — 把你的话听得懂 is wrong. Say 听得懂你的话 instead.

Do not confuse 不能 with 不 + result: 不能听懂 sounds stilted and usually means "not permitted to understand", not "unable". Prefer 听不懂.

Watch the fixed negative pairs: 来不及 (cannot make it in time) and 受不了 (cannot stand it). These are lexicalized and should be learned as whole expressions rather than assembled on the fly.